Tires

There is no way to calculate the extra wear from multiple axles since tire size, load, placement of the load on the trailer, service conditions, etc. all would have an inpact on the wear rates of each tire in each axle position. It is safe to say that no matter what the set of conditions, the trailer will tend to pivot on one of the axles and drag the tires on the remaining axles a bit sideways. This, of course, will wear these tires more quickly than the tires on the "rotating" axle. The farther the axle from the "rotating" axle, the more the scrubbing will take place.

Goodyear's position on siping is that it may, under certain operating conditions, improve tire performance. In particular, traction may be improved in wet or winter condtions. However, under the vast majority of truck operating conditions, new tires are designed with tread patterns and compounds that do not require siping for satisfactory performance. From a treadwear standpoint, there are some cases where siping has helped tires wear more evenly. For more information on siping go to http://www.goodyear.com/truck/pdf/radialretserv/Retread_S12_V.pdf This is Section 12 out of our Radial Truck Tire and Retread Service Manual and includes a few paragraphs on siping.